Fig. 1

Patient in the sixties with T2 lower rectal cancer. a CTC imaging of the tumor with MPR revealing a tumor 30 mm in size. b The macroscopic appearance of the tumor showing an irregular ulceration and clear marginal swelling. c MPR images showing the tumor not reach the marginal vessels (arrow) with smooth outer border. d A resected specimen showing tumor invasion to the muscularis propria, but without marginal vessel involvement (arrow), resulting in pathological stage T2